Top down integration testing

Top down Testing : In this approach testing is conducted from main module to sub module. STUB is used for simulate the submodule. Advantages: - Advantageous if major flaws occur toward the top of the program. It requires the highest-level modules be test and integrated first. This allows high-level logic and data flow to be tested early in the process and it tends to minimize the need for drivers.

Top - down testing is an approach to integrated testing where the top integrated modules are tested and the branch of the module is tested step by step until the end of the related module.

Sandwich testing is an approach to combine top down testing with bottom up testing. One limitation to this sort of testing is that any . It takes help of stubs for testing. It is known as top down or top to bottom approach.

In top down integration , first control hierarchy is identified. Top - down integration is an incremental approach to construction of program structure. In Top - Down integration testing , the testing takes place from top to bottom, following the control flow or architectural structure.

Here, only the top module is unit tested in isolation, after which, the lower modules are integrated one by one.

Topdown and bottom up approach in testing are the two procedures of data preparing and information requesting, utilized as a part of a range of fields including programming, humanistic and logical theories and administration or association. Top down integration is primarily considering as an approach where modules are developed and testing of that modules always starting at the finest level of the programming hierarchy and continuing towards the lower levels. Top down strategy of integration testing is an incremental approach because we proceed one . Well, the former tests only the interactions between the units while the latter tests the entire system.

As there is very much possibility that the lower level modules might not have been developed while beginning with top level . Test higher levels first ( controlling modules). Integration testing is done by a specific integration tester or test team. Implement stubs to deliver responses. Use tested modules as drivers.

Many stubs may be needeed. Must provide values as expected by . Stubs may be problematic to write. This technique starts from the topmost module and gradually progress towards the lower modules. Different approaches to integration testing. Only the top module is unit tested in isolation.

After this, the lower modules are integrated one by one. The process is repeated until all the modules are integrated and tested.